Up to now, a number of assembly apparatuses that perform assembly work using robot arms have been used. Recently, there is a demand for an assembly apparatus that achieves assembly work using robot arms instead of manual assembly work. In the manual assembly work, a human cell production system is introduced in which conveyers are removed and a person directly conveys workpieces. Meanwhile, there is a demand for replacing the human cell production system with a robot cell production system. In order to replace the human cell production system with the robot cell production system, there is a need to use a plurality of robot arms so as to widen the operating ranges thereof, increase the operating distance, and be able to perform operation from any direction, without increasing the apparatus size compared to a human cell production system. In this regard, there is known an assembly apparatus which includes two robot arms and an assembly work table and which is capable of performing assembly work (see PTL 1).